Systems for a turbocharger

A turbocharger, comprising:

• a turbine case housing a turbine wheel and a compressor case housing a compressor wheel of a compressor, the turbine case including a vaneless turbine nozzle integrated together as one piece with a remainder of the turbine case, wherein the turbine case includes a first flange;
• a water-cooled bearing case surrounding a shaft connecting the turbine wheel to the compressor wheel and arranged between and in face-sharing contact with each of the turbine case and compressor case, the water-cooled bearing case including a water jacket surrounding the shaft, the water jacket including an annular portion and a plurality of extending portions extending radially outward from the annular portion, relative to the shaft, and spaced apart from one another around a circumference of the annular portion, wherein the water-cooled bearing case includes a second flange, wherein the first flange and the second flange have face-sharing contact with one another, wherein a thermal relief groove is depressed into a face of the second flange that has face-sharing contact with the first flange, and wherein the water jacket extends into a portion of the second flange;
• and
• a plurality of fasteners arranged around a circumference of the turbine case, each fastener of the plurality of fasteners extending parallel to the shaft and from an outer face of a compressor end of the bearing case, through the bearing case, outside of the annular portion of the water jacket, and into the turbine case, where each fastener is positioned between a different pair of adjacent extending portions of the water jacket.

A turbocharger, comprising:

• a non-actively cooled turbine case housing a turbine wheel and a compressor case housing a compressor wheel;
• a water-cooled bearing case surrounding a shaft connecting the turbine wheel to the compressor wheel and arranged between the turbine case and compressor case;
• a plurality of slots arranged around a circumference of the turbine case, each slot including a slot length and a slot diameter, the slot length longer than the slot diameter, the plurality of slots including four slots positioned 90 degrees apart from one another around a circumference of the turbine case, where the slot length of each slot is arranged in a radial direction relative to the shaft;
• and
• a plurality of dowel pins, each dowel pin positioned within a corresponding slot and coupling a first flange of the turbine case to a second flange of the bearing case, each dowel pin having a diameter smaller than the slot length and sized to have a tight fit with the slot diameter of the corresponding slot,
• wherein the first flange and second flange have face-sharing contact with one another, wherein a thermal relief groove is depressed into a face of the second flange that has face-sharing contact with the first flange, and wherein the bearing case includes a water jacket surrounding the shaft and extending into a portion of the second flange arranged proximate to the first flange.